Electrochromic device

ABSTRACT

An electrochromic device according to an embodiment comprises a transparent conductive layer, an ion storage layer, an electrolyte layer, an electrochromic layer, and a reflective layer or a transparent conductive layer, wherein the ion storage layer includes an iridium atom and a tantalum atom, wherein the electrolyte layer includes a tantalum atom, wherein the electrochromic layer includes a tungsten atom, wherein at least one of the tungsten atom of the electrochromic layer and the iridium atom and the tantalum atom of the ion storage layer is hydrogenated, wherein the reflective layer is non-porous.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/KR2017/002406, filed Mar. 6, 2017, which claims the benefit under 35U.S.C. § 119 of Korean Application No. 10-2016-0027014, filed Mar. 7,2016, and Korean Application No. 10-2016-0055494, filed May 4, 2016,each of which is herein incorporated by reference in its entirety.

BACKGROUND Technological Field

The described technology relates to an electrochromic device, and morespecifically, relates to an electrochromic device capable of beinguniformly discolored and decolorized by including a co-depositedhydrogenated compound and including a non-porous reflective layer ortransparent conductive layer.

Description of the Related Technology

Electrochromism is a phenomenon in which, when a voltage is applied, acolor is reversibly changed due to a direction of an electric field, anda material having an optical property reversibly changeable due to anelectrochemical oxidation-reduction reaction with the above-describedproperty is called an electrochromic material. The electrochromicmaterial has a property in which, while an electrochromic material isnot colored in a case in which an external electrical signal is notapplied thereto, the electrochromic material is colored when an externalelectrical signal is applied thereto, or conversely, while anelectrochromic material is colored in a case in which an externalelectrical signal is not applied thereto, the electrochromic material isdecolored when an external electrical signal is applied thereto.

An electrochromic device is an device in which optical transmissionproperties are changed such that a color of an electrochromic materialis changed due to an electrical oxidation-reduction reaction accordingto application of a voltage. A demand for the electrochromic devicecapable of selectively transmitting light currently increases in varioustechnical fields. The electrochromic device may be applied to variousfields including smart windows, smart mirrors, display devices, andcamouflage devices.

The electrochromic device includes a layer of an electrochromic materialinto which ions and electrons can be reversibly and simultaneouslyinserted, and oxidation states of the ions and electrons correspond tothe states of insertion and ejection, and oxidation states of the ionsand electrons are different colored when ions and electrons are suppliedthrough a suitable power source, and one of the states has greater lighttransmission than that of the other state. A general main raw materialof the electrochromic material is tungsten oxide, and for example, theelectrochromic material has to be in contact with an electron source,such as a transparent electrically conductive layer, and an ion(positive ion or negative ion) source such as an ion conductiveelectrolyte. In addition, it has been known that a counter electrodecapable of reversibly inserting positive ions, macroscopically, shouldbe related to the layer of an electrochromic material symmetrically withrespect to the layer of an electrochromic material such that anelectrolyte serves as a single ion medium. A main raw material of thecounter electrode has to be a layer which has a natural color, or is atleast transparent or is hardly colored in a state in which theelectrochromic layer is colored.

An anionic electrochromic material including nickel oxide or iridiumoxide as a main raw material is generally used as a counter electrodebecause tungsten oxide is a cationic electrochromic material, i.e., itscolored state corresponds to the most reduced state. In addition, it hasbeen also proposed to use optically neutral material in correspondingoxidation state, for example a cerium oxide such as an electricallyconductive polymer (polyaniline) or Prussian blue or an organicmaterial.

In Korean Patent Publication No. 2011-0043595, an electricallycontrollable panel, in particular an electrochromic device havingintended controlled infrared reflection to form a window pane isdisclosed. In U.S. Patent Publication No. 2007-0058237, anelectrochromic element of a multilayer system including an ion storagelayer, a transparent solid electrolyte layer, an electrochromic layer,and a reflective layer is disclosed.

However, in Korean Patent Publication No. 2011-0043595, iridium is usedalone as a main raw material of an ion storage layer. In this case,there are problems in that the iridium is decomposed because the iridiumis weak to ultraviolet (UV) light or moisture, a short circuit occurswhen the iridium is in direct contact with tungsten, and the like. InU.S. Patent Publication No. 2007-0058237, there are problems in that acomplex process has to be performed to form a porous reflective layersuch that water or water molecules can pass therethrough and the like.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

The described technology has been made to solve the above-mentionedproblems occurring in the related art, as iridium and tantalum,preferably a hydrogenated iridium and a hydrogenated tantalum, aresimultaneously deposited, problems in that iridium is decomposed becausethe iridium is weak to ultraviolet (UV) light or moisture, a shortcircuit occurs when the iridium is in direct contact with tungsten, andthe like, which occur when only the iridium is used in theelectrochromic device, are solved, and as a co-deposited hydrogenatedcompound is used, an electrochromic device capable of forming anon-porous reflective layer through a simple process without forming aporous reflective layer through a complex process for injecting ionsneeded to electrically discolor by moving water molecules is provided.

An electrochromic device according to an embodiment comprises atransparent conductive layer, an ion storage layer, an electrolytelayer, an electrochromic layer, and a reflective layer or a transparentconductive layer, wherein the ion storage layer includes an iridium atomand a tantalum atom, wherein the electrolyte layer includes a tantalumatom, wherein the electrochromic layer includes a tungsten atom, whereinat least one of the tungsten atom of the electrochromic layer and theiridium atom and the tantalum atom of the ion storage layer ishydrogenated, wherein the reflective layer is non-porous.

wherein the transparent conductive layer includes at least one kind ofoxide selected from an indium zinc oxide (IZO), an indium tin oxide(ITO), an aluminum doped zinc oxide (AZO), a boron doped zinc oxide(BZO), a tungsten doped zinc oxide (WZO) and a tungsten doped tin oxide(WTO), a fluorine doped tin oxide (FTO), a gallium doped zinc oxide(GZO), an antimony doped tin oxide (ATO), an indium doped zinc oxide(IZO), a niobium doped titanium oxide and a zinc oxide (ZnO).

wherein the ion storage layer includes 20-38 wt % of iridium atoms.

wherein the ion storage layer includes a hydrogenated iridium oxide of aformula H_(a)lrO₂ (herein, 0<a<2) and a hydrogenated tantalum oxide of aformula H_(b)Ta₂O₅ (herein, 0<b<5).

wherein the electrochromic layer includes a hydrogenated tungsten oxideof a formula H_(c)WO₃ (herein, 0<c<3).

wherein the reflective layer comprises at least one kind of materialselected from an aluminum, a silver, a rubidium, a molybdenum, achromium, a ruthenium, a gold, a copper, a nickel, a lead, a tin, anindium and a zinc.

a thickness of the transparent conductive layer is 150-800 nm, athickness of the ion storage layer is 50-500 nm, a thickness of theelectrolyte layer is 180-800 nm, a thickness of the electrochromic layeris 140-650 nm, and a thickness of the reflective layer is 30-280 nm.

wherein the ion storage layer includes 14.9-73.3 wt % of iridium atoms.

wherein the ion storage layer includes 14.9-59.8 wt % of iridium atoms.

wherein the ion storage layer includes 14.9-23.2 wt % of iridium atoms.

wherein the ion storage layer includes 20.2-23.2 wt % of iridium atoms.

In an electrochromic device according to the described technology, thereis an effect in that, since iridium and tantalum, preferably ahydrogenated iridium and a hydrogenated tantalum, are simultaneouslydeposited, problems in which iridium is decomposed because the iridiumis weak to ultraviolet (UV) light or moisture, a short circuit occurswhen the iridium directly is in contact with tungsten, and the like,which occur when only the iridium is used in the electrochromic device,are solved, and there is an effect in that, since a co-depositedhydrogenated compound is used, a non-porous reflective layer can beformed through a simple process in which hydrogen ions are directlyinjected during the process without injecting ions needed toelectrically discolor by moving water molecules.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating a structure of an electrochromic deviceaccording to one embodiment of the described technology.

FIG. 2 is a view illustrating a surface of a porous thin film containinghydrogenated tungsten.

FIG. 3 is a photograph showing a thickness of the thin film containingthe hydrogenated tungsten.

FIG. 4 is a view illustrating a surface of a thin film on whichhydrogenated tantalum and hydrogenated iridium are co-deposited.

FIG. 5 is a view related to a thickness of the thin film on which thehydrogenated tantalum and the hydrogenated iridium are co-deposited.

FIG. 6 is a graph of a measurement result of a transmittance of the thinfilm on which the hydrogenated tantalum and the hydrogenated iridium areco-deposited.

FIG. 7 is a graph of a measurement result of electric power applied tothe thin film when the transmittance of the thin film on which thehydrogenated tantalum and the hydrogenated iridium are co-deposited ismeasured.

FIG. 8 is a graph of a measurement result of a transmittance of the thinfilm containing the hydrogenated tungsten.

FIG. 9 is a graph of a measurement result of electric power applied tothe thin film when the transmittance of the thin film containing thehydrogenated tungsten is measured.

FIGS. 10A-F are graphs showing a ratio of current to a voltage appliedto an ion storage layer according to an iridium weight ratio of the ionstorage layer according to a first embodiment.

FIG. 11 is a schematic view illustrating an electrochromic deviceaccording to a second embodiment of the described technology.

FIG. 12 is a cross-sectional view taken along line I-I′ of FIG. 11.

FIGS. 13 to 17 are a manufacturing process diagram of FIG. 12.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

Advantages and features of the described technology and methods ofachieving the same should be clearly understood with reference to theaccompanying drawings and the following detailed embodiments. However,the described technology is not limited to the embodiments to bedisclosed, and may be implemented in various different forms. Theembodiments are provided in order to fully explain the describedtechnology and fully explain the scope of the described technology tothose skilled in the art. The described technology is only defined bythe scope of the claims.

Unless otherwise defined, all terms (including technical and scientificterms) used herein may be used in a sense commonly understood by one ofordinary skill in the art to which the described technology belongs.Also, commonly used predefined terms are not ideally or excessivelyinterpreted unless explicitly defined otherwise.

Hereinafter, an electrochromic device according to the describedtechnology will be described in detail.

As shown in FIG. 1, the electrochromic device according to a firstembodiment of the described technology may be an electrochromic devicein which a reflective layer 110 or a transparent conductive layer 120,an intermediate layer 130 and a transparent conductive layer 170 stackedin this order, wherein the intermediate layer 130 may include anelectrochromic layer 140, electrolyte layer 150 and ion storage layer160, wherein the ion storage layer may include an iridium atom and atantalum atom, wherein the electrolyte layer may include a tantalumatom, wherein at least one of the tungsten atom of the electrochromiclayer and the iridium atom and the tantalum atom of the ion storagelayer may be hydrogenated, wherein the reflective layer may benon-porous.

wherein the transparent conductive layer may include at least one kindof oxide selected from an indium zinc oxide (IZO), an indium tin oxide(ITO), an aluminum doped zinc oxide (AZO), a boron doped zinc oxide(BZO), a tungsten doped zinc oxide (WZO) and a tungsten doped tin oxide(WTO), a fluorine doped tin oxide (FTO), a gallium doped zinc oxide(GZO), an antimony doped tin oxide (ATO), an indium doped zinc oxide(IZO), a niobium doped titanium oxide and a zinc oxide (ZnO).

In the electrochromic device according to the described technology, theion storage layer 160 is a layer for supplying deficient ions to theelectrolyte layer 150, the ion storage layer may include iridium andtantalum atoms. When only iridium atoms are used in the ion storagelayer 160 and are in contact with tungsten atoms, a short circuit mayoccur, in addition, in a case in which another material is stacked on alayer containing only iridium atoms, energy thereof may be lost, inaddition, since the iridium atoms are weak to moisture, a problem mayoccur in a case in which moisture permeates the layer containing onlyiridium atoms, and couplings between the iridium atoms may be decomposedby ultraviolet (UV) light, therefore, co-deposition of the iridium atomsand the tantalum atoms is preferable because of obtaining strength(durability) and solving problems in that.

The ion storage layer preferably includes 20 to 38 wt % of iridiumatoms, and more preferably includes 23 to 33 wt % of iridium atoms. Whenthe ion storage layer includes less than 20 wt % of iridium atoms, it isnot preferable because an electrochromic reaction does not occur, andwhen the ion storage layer includes greater than 38 wt % of iridiumatoms, it is not preferable because the ion storage layer reacts with UVlight to deteriorate and an effect of discoloration of the ion storagelayer is reduced, or the ion storage layer may be fixed to have a redcolor, and a durability-related problem may occur.

Alternatively, the ion storage layer preferably includes 15 wt % to 70wt % of iridium atoms, the ion storage layer more preferably includes 15wt % to 60 wt % of iridium atoms, and the ion storage layer furtherpreferably includes 15 wt % to 23 wt % of iridium atoms. When the ionstorage layer includes less than 15 wt % of iridium atoms, it is notpreferable because an electrochromic reaction does not occur, and whenthe ion storage layer includes greater than 70 wt % of iridium atoms,there is hardly any change in transmittance even when an electric fieldis generated.

In the ion storage layer, the iridium may be a hydrogenated iridiumoxide having a formula of H_(a)IrO₂ (here, 0<a<2), the tantalum may be ahydrogenated tantalum oxide having a formula of H_(b)Ta₂O₅ (here,0<b<5), and since the ion storage layer includes hydrogenated iridiumoxide and hydrogenated tantalum oxide as described above, an additionalprocess for injecting hydrogen ions into the ion storage layer does notneed for an oxidation-reduction reaction.

In the electrochromic device according to the described technology, theelectrolyte layer may serve to transmit ions, may be divided into aliquid electrolyte and a solid electrolyte according to physicalproperties of a film, be divided into a proton electrolyte and an alkaliion electrolyte according to kinds of an ion transmission material, andthe electrolyte layer may include tantalum atoms, more preferably mayinclude tantalum oxide (Ta₂O₅).

In the electrochromic device according to the described technology, theelectrochromic layer is a layer which is in charge of discoloration andin which a change rate of color due to application of electricity ishigh. More specifically, the electrochromic layer may be formed of aliquid or solid electrochromic material, and the electrochromic materialis a material having an electrochromic property in which opticalabsorbance is changed due to electrochemical oxidation and reductionreactions, electrochemical oxidation and reduction phenomena of theelectrochromic material reversibly occur according to whether or not avoltage is applied and a magnitude of a voltage, and therefore,absorbance and transparency of the electrochromic material may bereversibly changed.

As illustrated in FIG. 1, the electrochromic layer 140 may be formedbetween the electrolyte layer 150 and the reflective layer 110 or thetransparent conductive layer 120, may receive electricity applied fromthe transparent conductive layer 120 or the reflective layer 110, andmay be colored or decolorized through an oxidation or reductionreaction. That is, the electrochromic layer 140 may be colored ordecolorized through the oxidation or reduction reaction occurring due tomovement of hydrogen by an electric field generated by a voltage appliedto the transparent conductive layer 170 located thereon and thetransparent conductive layer 120 or reflective layer 110 locatedtherebelow.

In addition, due to the electric field, the ion storage layer 160 mayalso be colored or decolored through the reduction or oxidationreaction. In a case in which a reduction reaction occurs in theelectrochromic layer 140 due to the electric field, an oxidationreaction may occur in the ion storage layer 160, and in a case in whichan oxidation reaction occurs in the electrochromic layer 140 due to theelectric field, an oxidation reaction may occur in the ion storage layer160. The electrochromic layer 140 may be colored due to the reductionreaction, and may be decolorized due to the oxidation reaction. The ionstorage layer 160 may be colored due to the oxidation reaction, and maybe decolorized due to the reduction reaction.

In the case in which the electrochromic layer 140 is colored, the ionstorage layer 160 may also be colored, and in the case in which theelectrochromic layer 140 is decolorized, the ion storage layer 160 mayalso be decolorized.

The electrochromic layer may be a tungsten layer, and the tungsten layermay include tungsten atoms, the tungsten may be hydrogenated tungsten,and the hydrogenated tungsten may have a formula of HcWO₃ (here, 0<c<3).

In the described technology, in the case in which hydrogenated tungstenis used in the electrochromic layer, it is preferable because ioninjection is not needed for the oxidation-reduction reaction in theelectrochromic layer.

In the electrochromic device according to the described technology, thereflective layer 110 serves as a reflective plate configured to reflectlight passing through the electrochromic layer and incident thereon anda counter electrode against the transparent conductive layer 170, and inthe conventional art, a reflective layer is formed to be porous so thatwater or water molecules pass therethrough. However, in the describedtechnology, since at least one of the ion storage layer 160 and theelectrochromic layer 140 includes a hydrogenated metal oxide, thereflective layer 110 according to the described technology may be formedof a non-porous pure metal film.

The reflective layer 110 is not particularly limited, and may include atleast one material among, for example, aluminum, silver, rubidium,molybdenum, chromium, ruthenium, gold, copper, nickel, lead, tin,indium, and zinc.

It is preferable that a thickness of the transparent conductive layer be150 to 800 nm, a thickness of the ion storage layer be 50 to 500 nm, athickness of the electrolyte layer be 180 to 800 nm, a thickness of theelectrochromic layer be 140 to 650 nm, and a thickness of the reflectivelayer be 30 to 280 nm.

When the thickness of the transparent conductive layer is less than 150nm, it is not preferable because electrical conductivity is notsufficient.

When the thickness of the transparent conductive layer is greater than800 nm, it is not preferable because the transparent conductive layerbecomes opaque or transparency is reduced.

When the thickness of the ion storage layer is less than 50 nm, since astorage amount of ions is not sufficient, a discoloration effect isdifficult to manifest, and thus it is not preferable. When the thicknessof the ion storage layer is greater than 500 nm, since the ion storagelayer is too thick, the ions may not escape from the ion storage layerwithin a sufficient time due to the thickness while the ions move, andthus it is not preferable.

When the thickness of the electrolyte layer is less than 180 nm, sincethe ion storage layer and the electrochromic layer located above andbelow the electrolyte layer may be in contact with each other, and thusit is not preferable. When the thickness of the electrolyte layer isgreater than 800 nm, since the electrolyte layer blocks movement of theions, an electrochromic effect is difficult to manifest, and thus it isnot preferable.

When the thickness of the electrochromic layer is less than 140 nm,since the electrochromic layer may not sufficiently react with the ions,a discoloration phenomenon becomes very weak, and thus it is notpreferable. When the thickness of the electrochromic layer is greaterthan 650 nm, since a magnitude of an electric field may be reduced,movement of the ions may be disturbed, and thus it is not preferable.

When the thickness of the reflective layer is less than 30 nm, sincereflection and transmission simultaneously occur, the reflective layerdoes hardly serve as a reflective layer, and thus it is not preferable.When the thickness of the reflective layer is greater than 280 nm, sincean electric resistance thereof increases, a total power consumption ofthe device increases, and thus it is not preferable.

Although not illustrated in the drawings, a first substrate may beformed on one surface of the transparent conductive layer 120 and asecond substrate may be formed on one surface of the reflective layer110 or the transparent conductive layer 120, and electrode connectionpart may be additionally formed at one end of the first and secondsubstrates.

In the electrochromic device according to the described technology, atransmittance of a thin film including the hydrogenated tantalum and thehydrogenated iridium which are co-deposited on the ion storage layer ismeasured, results of decolorization and discoloration according to awavelength are shown in the following Table 1 and FIG. 6, and ameasurement result of a range of an electric power supply when theelectrochromic device is operated is shown in the following Table 2 andFIG. 7.

TABLE 1 Transmittance Measurement Wavelength DecolorizationDiscoloration Difference (ΔT) 400 66.4 24.1 42.4 450 94.7 39.1 55.7 50082.4 41.9 40.5 550 89.5 41.7 47.8 600 99.5 41.8 57.7 650 98.2 44.9 53.2700 92.5 50.1 42.5 750 88.8 55.7 33.2 800 87.8 62.7 25.0

TABLE 2 Voltage Current Electric power Driving (V) (mA) (mW/cm2)Discoloration 1.2 2.0 2.4 Decolorization −0.3 −1.5 0.4

In addition, in the electrochromic device according to the describedtechnology, a transmittance of the electrochromic layer is measured,results of decolorization and discoloration according to a wavelengthare shown in Table 3 and FIG. 8, and a measurement result of a range ofan electric power supply when the electrochromic device is operated isshown in Table 4 and FIG. 9.

TABLE 3 Transmittance Measurement Wavelength DecolorizationDiscoloration Difference ΔT 425 71.3 22.8 48.6 550 93.6 9.8 83.8 68096.7 5.3 91.4 800 90.0 4.3 85.6 1200 85.1 4.7 80.3 1500 67.1 6.4 60.72500 34.1 7.4 26.7 2800 25.3 5.2 20.1

TABLE 4 Voltage Current Electric power Driving (V) (mA) (mW/cm2)Discoloration −1.0 −21.7 21.7 Decolorization 0.6 20.3 12.8

FIG. 10 is showing a ratio of current to a voltage applied to an ionstorage layer according to a weight ratio of iridium of the ion storagelayer according to a first embodiment.

Table 5 is a table showing total amperage and transmittance according toa weight ratio of iridium of the ion storage layer when the ion storagelayer is colored or decolorized.

TABLE 5 Transmit- Iridium Tantalum tance at Transmit- Total Weight RatioWeight Ratio Decolor- tance at Amperage No. (wt %) (wt %) izationColoration (mA) 1 87.4 12.6 36.2 14.8 25 2 73.3 26.7 64.1 39.3 13 3 59.840.2 70.1 54 9 4 23.2 76.8 87.3 75.5 9 5 20.0 80.0 85.3 72.3 8 6 14.985.1 82.5 74.1 7

In Table 5 and FIG. 10, the iridium weight ratio is a weight ratio ofthe iridium to the total weight of iridium atoms and tantalum atoms inthe whole ion storage layer, the transmittance is a transmittance of theion storage layer, and the total amperage is a current between bothsurfaces of the ion storage layer. That is, the total amperage is acurrent flowing across the ion storage layer when a voltage is appliedbetween an upper surface and a lower surface of the ion storage layer.

In FIG. 10, a main change region A is a section in which amperagelinearly increases or decreases according to an increase or decrease ina voltage. The main change region A may be a main coloration section ormain decolorization section. That is, in the electrochromic device,there has to be a section in which as the voltage increases, a movementamount of ions increases, and thus an ion current increases, and as thevoltage decreases, a movement amount of ions decreases, and thus the ioncurrent decreases, so that desired coloration or decolorization mayoccur. That is, there has to be the main change region A in which theamperage is linearly changed according to the increase or decrease inthe voltage, so that the coloration or decolorization of theelectrochromic device may control. In addition, as the main changeregion A is larger, a function of the electrochromic device may be moreimproved.

FIG. 10A is a graph showing a voltage-current curve of an electrochromicdevice in which a ratio of the iridium atoms is 87.5 wt % and a ratio ofthe tantalum atoms is 12.6 wt %. In FIG. 10A, there is no region A inthe voltage-current curve, and the electrochromic device has atransmittance of 36.2 when decolorized, and has a transmittance of 14.8when colored. Since the electrochromic device has the transmittance of36.2 when decolorized, a transmittance thereof is low even in adecolorization mode, and thus the electrochromic device cannot serve tofunction as an electrochromic device.

FIG. 10B is a graph showing a voltage-current curve of an electrochromicdevice in which a ratio of the iridium atoms is 26.7 wt % and a ratio ofthe tantalum atoms is 39.3 wt %. In FIG. 10B, there is a small mainchange region A in a region adjacent to 1.5 V in the voltage-currentcurve, and a coloration or decolorization reaction occurs in a range ofabout 1.4 V to 1.5 V. The electrochromic device has a transmittance of64.1 when decolorized, and a transmittance of 39.3 when colored. Thatis, in a case in which an electrochromic device is formed with an ionstorage layer of FIG. 10B, a device having a maximum transmittance of64.1 may be formed.

FIG. 10C is a graph showing a voltage-current curve of an electrochromicdevice in which a ratio of the iridium atoms is 59.8 wt % and a ratio ofthe tantalum atoms is 40.2 wt %. In FIG. 10C, there is a small mainchange region A in a region adjacent to 1.5 V in the voltage-currentcurve, and a coloration or decolorization reaction occurs in a range ofabout 1.4 V to 1.5 V. The electrochromic device has a transmittance of70.1 when decolorized, and a transmittance of 54 when colored. That is,in a case in which an electrochromic device is formed with an ionstorage layer of FIG. 10C, a device having a maximum transmittance of70.1 may be formed. Since the ion storage layer having the weight ratiosof FIG. 10C has a larger main change region A and a higher maximumtransmittance than the ion storage layer having the weight ratios ofFIG. 10B, an electrochromic device having a better effect may be formed.

FIG. 10D is a graph showing a voltage-current curve of an electrochromicdevice in which a ratio of the iridium atoms is 23.2 wt %, and a ratioof the tantalum atoms is 76.8 wt %. In FIG. 10D, there is a small mainchange region A in a region adjacent to 1.5 V in the voltage-currentcurve, and a coloration or decolorization reaction occurs in a range ofabout 1.3 V to 1.5 V. The electrochromic device has a transmittance of87.3 when decolorized, and a transmittance of 75.5 when colored. Thatis, in a case in which an electrochromic device is formed with an ionstorage layer of FIG. 10D, a device having a maximum transmittance of87.3 may be formed. Since the ion storage layer having the weight ratiosof FIG. 10D has a larger main change region A and a higher maximumtransmittance than the ion storage layer having the weight ratios ofFIG. 10C, an electrochromic device having a better effect may be formed.In addition, since the transmittance thereof rapidly increases when theelectrochromic device is decolorized, the electrochromic device may beused in a vehicle mirror, a vehicle glass, or a building glass.

FIG. 10E is a graph showing a voltage-current curve of an electrochromicdevice in which a ratio of the iridium atoms is 20.0 wt % and a ratio ofthe tantalum atoms is 80.0 wt %. In FIG. 10E, there is a small mainchange region A in a region adjacent to 1.5 V in the voltage-currentcurve, and a coloration or decolorization reaction occurs in a range ofabout 1.25 V to 1.5 V. The electrochromic device has a transmittance of85.3 when decolorized, and a transmittance of 72.3 when colored. Thatis, in a case in which an electrochromic device is formed with an ionstorage layer of FIG. 10E, a device having a maximum transmittance of85.3 may be formed. Since the ion storage layer having the weight ratiosof FIG. 10E has a larger main change region A and a higher maximumtransmittance than the ion storage layer having the weight ratios ofFIG. 10C, an electrochromic device having a better effect may be formed.

FIG. 10F is a graph showing a voltage-current curve of an electrochromicdevice in which a ratio of the iridium atoms is 14.9 wt % and a ratio ofthe tantalum atoms is 85.1 wt %. In FIG. 10F, there is a small mainchange region A in a region adjacent to 1.5 V in the voltage-currentcurve, and a coloration or decolorization reaction occurs in a range ofabout 1.25 V to 1.5 V. The electrochromic device has a transmittance of82.5 when decolorized, and a transmittance of 74.1 when colored. Thatis, in a case in which an electrochromic device is formed with an ionstorage layer of FIG. 10F, a device having a maximum transmittance of82.5 may be formed. Since the ion storage layer having the weight ratiosof FIG. 10F has a larger main change region A and a higher maximumtransmittance than the ion storage layer having the weight ratios ofFIG. 10C an electrochromic device having a better effect may be formed.However, a change range of transmittance of the ion storage layer ofFIG. 10F is slightly reduced than those of the ion storage layers ofFIG. 10D and FIG. 10E when the electrochromic device isdecolorized/colored. That is, the change range of transmittance of FIG.10D is 11.8 when the electrochromic device is decolorized/colored, andthe change range of transmittance of FIG. 10E is 13 when theelectrochromic device is decolorized/colored, whereas the change rangeof transmittance of FIG. 10F is 8.4 when the electrochromic device isdecolorized/colored. Accordingly, since the change range oftransmittance of the ion storage layer of FIG. 10F when theelectrochromic device is decolorized/colored is less than those of theelectrochromic devices having the ion storage layers of FIG. 10D andFIG. 10E when the electrochromic device is decolorized/colored, anelectrochromic efficiency is slightly reduced.

As described above, the ratio of the iridium atoms of the ion storagelayer may be in a range of 14.9 wt % to 73.3 wt %. In a case in whichthe ratio of the iridium atoms is less than 14.9 wt %, there is noelectrochromic effect, and in a case in which the ratio is greater than73.3 wt %, transmittance is low even when the electrochromic device isdecolorized, and thus the above-described electrochromic device cannotserve to function as the electrochromic device.

Preferably, the ratio of the iridium atoms of the ion storage layer maybe in a range of 14.9 wt % to 59.9 wt %. In a case in which the ratio ofthe iridium atoms is less than 14.9 wt %, there is no electrochromiceffect, and in a case in which the ratio is greater than 59.9 wt %,since the main change region is small, efficiency of the electrochromicdevice decreases.

More preferably, the ratio of the iridium atoms of the ion storage layermay be in a range of 14.9 wt % to 23.2 wt %. In this range, since theion storage layer has a transmittance of 80 or more when theelectrochromic device is decolorized, the transmittance is outstandinglygreater than that of the ion storage layer having other ranges of aratio of the iridium atoms, and thus the electrochromic device may beused in a vehicle mirror, a vehicle glass, or a building glass.

More preferably, the ratio of the iridium atoms of the ion storage layermay be in a range of 20.0 wt % to 23.2 wt %. In this range, since theion storage layer has a transmittance of 80 or more when theelectrochromic device is decolorized, the transmittance is outstandinglygreater than that of the ion storage layer having other ranges of aratio of the iridium atoms, the ion storage layer may have a changerange of transmittance of 10 or more when the electrochromic device isdecolorized/colored, and thus there is an effect in that a device havinga large electrochromic efficiency can be formed.

FIG. 11 is a schematic view illustrating an electrochromic deviceaccording to a first embodiment of the described technology, and FIG. 12is a cross-sectional view taken along line I-I′ of FIG. 11.

Referring to FIGS. 11 and 12, the electrochromic device according to theanother embodiment of the described technology includes a firstconductive layer 210, a second conductive layer 270, and an intermediatelayer 230.

The first conductive layer 210 and the second conductive layer 270 arelocated between an upper substrate (not shown) and a lower substrate(not shown) formed of transparent materials such as glass or the like,and formed to opposite to each other.

Here, the first conductive layer 210 and the second conductive layer 270are formed using a sputtering deposition method or the like, may supplyelectric power, and are thin film oxide conductive layers capable ofinducing electrochromism.

In addition, the first conductive layer 210 may be a transparentmaterial such as indium tin oxide (ITO), indium zinc oxide (IZO),aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO),tungsten-doped zinc oxide (WZO), or tungsten-doped tin oxide (WTO).

In a case in which the second conductive layer 270 is a transparentelectrode, the second conductive layer 270 may be the same material asthat of the first conductive layer 210, and in a case in which thesecond conductive layer 270 is used as a reflective film, the secondconductive layer 270 may be a reflective material configured to reflectlight, such as aluminum, ruthenium, chromium, silver (Ag), rubidium,molybdenum, gold (Au), copper (Cu), nickel (Ni), lead (Pb), tin (Sn),indium (In), or zinc (Zn). That is, the second conductive layer 270 maybe selectively formed as the transparent electrode or reflective film.

In the case in which the second conductive layer 270 is formed as thereflective film, the second conductive layer 270 serves as a reflectiveplate configured to reflect incident light passing through anelectrochromic layer 260 of the intermediate layer 230, which will bedescribed below, and as a counter electrode against the first conductivelayer 210.

That is, although a reflective layer is formed to be porous so thatwater or water molecules have to pass therethrough in the related art,in the described technology, since at least one of an electrochromiclayer 260 and an ion storage layer 240 of the intermediate layer 230,which will be also described below, includes a hydrogenated metal oxide,the second conductive layer 270 of the described technology may beformed of only a non-porous pure metal film.

Since the second conductive layer 270 is formed to be non-porous,permeation of external moisture into the intermediate layer 230 may beprevented.

The intermediate layer 230 includes an electrolyte layer 250, the ionstorage layer 240, and the electrochromic layer 260. First, theelectrolyte layer 250 is formed between the first conductive layer 210and the second conductive layer 270 using a sputtering deposition methodand the like, and serves to transmit ions.

A material of the electrolyte layer 250 may be divided into a liquidelectrolyte and a solid electrolyte according to physical properties ofa film, and may be divided into a proton electrolyte and an alkali ionelectrolyte according to a kind of ion transmission material, and theelectrolyte layer 250 may include tantalum atoms, and may morepreferably include tantalum oxide (Ta2O5).

The ion storage layer 240 is formed to be located between the firstconductive layer 210 and the electrolyte layer 250 using a sputteringdeposition method and the like. Here, the ion storage layer 240preferably includes 20 to 38 wt % of iridium atoms, and more preferablyincludes 23 to 33 wt % of iridium atoms. When the ion storage layer 240includes less than 20 wt % of iridium atoms, an electrochromic reactiondoes not occur, and thus it is not preferable. When the ion storagelayer 240 includes greater than 38 wt % of iridium atoms, since the ionstorage layer 240 reacts with UV light to deteriorate and an effect ofdiscoloration of the ion storage layer may be reduced, or the ionstorage layer may be fixed to have a red color, or a durability-relatedproblem may occur, and thus it is not preferable.

The iridium may be a hydrogenated iridium having a formula of H_(a)IrO₂(here, 0<a<2), the tantalum may be a hydrogenated tantalum having aformula of H_(b)Ta₂O₅ (here, 0<b<5), and since the hydrogenated iridiumand tantalum are included as described above, an additional process forinserting hydrogen ions does not need for an oxidation-reductionreaction.

The electrochromic layer 260 is formed to be located between the secondconductive layer 270 and the electrolyte layer 250 using a sputteringdeposition method and the like, and is a layer configured to servediscoloration because of having a large color change rate by applicationof electricity.

In more detail, the electrochromic layer 260 may be formed of a liquidor solid electrochromic material having an electrochromic property inwhich optical absorbance is changed due to electrochemical oxidation andreduction reactions, and reversible electrochemical oxidation andreduction phenomena of the electrochromic material occur according towhether or not a voltage is applied and a magnitude of a voltage, andthus an optical absorbance and a transparency thereof may be reversiblychanged.

In addition, the electrochromic layer 260 may be formed between theelectrolyte layer 250 and the second conductive layer 270, receiveelectricity applied from the second conductive layer 270, and be coloredor decolorized through an oxidation or reduction reaction.

The electrochromic layer 260 includes tungsten atoms, the tungsten maybe a hydrogenated tungsten, and the hydrogenated tungsten may have aformula of HcWO₃ (here, 0<c<3).

In the described technology, it is preferable for the electrochromiclayer 260 to include the hydrogenated tungsten because ion insectioninto the electrochromic layer 260 is not needed for oxidation andreduction reactions.

In the above-described embodiment, the electrochromic layer 260 isformed on the electrolyte layer 250 and the ion storage layer 240 isformed below the electrolyte layer 250, but the ion storage layer 240may be formed on the electrolyte layer 250 and the electrochromic layer260 may be formed below the electrolyte layer 250 as necessary.

Meanwhile, a separation groove 280 is formed to pass through theelectrolyte layer 250 from the outside of the second conductive layer270 such that the electrolyte layer 250 is divided into an outer regionand an inner region.

Here, since the separation groove 280 separates the electrolyte layer250 into the inner region and the outer region, the separation groove280 may block electricity supplied from the outer region from beingtransmitted to the inner region. That is, since an ion flow in the innerregion may not be disturbed by the electricity of the outer region, anaccurate electrochromic effect may be achieved. In other words, since avoltage applied from the outer region is prevented from affecting theinner region, the accurate electrochromism can occur, and since avoltage applied to the inner region is prevented from being transmittedto the outer region, there is an effect of decrease in powerconsumption.

In the drawings, the separation groove 280 passes through theelectrolyte layer 250 and is formed to extend to a part of the ionstorage layer 240, and since it is sufficient for the separation groove280 to be formed to pass through only the electrolyte layer 250, theseparation groove 280 may not be formed in the ion storage layer 240.

That is, the separation groove 280 may pass through the secondconductive layer 270, the electrochromic layer 260, and the electrolytelayer 250, and may pattern at least a part of the ion storage layer 240.That is, the separation groove 280 may pattern a part or entirety of theion storage layer 240.

Preferably, one end of the separation groove 280 may be located betweenan upper surface and a lower surface of the ion storage layer 240. Sinceone end of the separation groove 280 is designed to be located betweenthe upper surface and the lower surface of the ion storage layer 240, aprocess margin may be secured. That is, connection of the electrolytelayer 250 occurring at both sides of the separation groove 280 due to anerror of the separation groove 280 may be prevented, and patterning onthe first conductive layer 210 due to an error of the separation groove280 may be prevented, so that there is an effect of preventingmanufacturing defects.

In addition, an interconnection groove 290 exposing an inner surface ofthe first conductive layer 210 to the outside is formed in the outerregion divided by the separation groove 280, and at least a part of theinterconnection groove 290 is filled to form a connection pattern 271connected to the inner surface of the first conductive layer 210. Thatis, the connection pattern 271 may be electrically connected to thefirst conductive layer 210 through the interconnection groove 290.

Here, the connection pattern 271 may be formed to cover an outer surfaceof the outer region divided by the separation groove 280, that is, anupper surface of the electrochromic layer 260. Since a minimum diameterof an electrical interconnect is generally several millimeters, it issubstantially impossible to directly insert an interconnect into theinterconnection groove 290 and connect the interconnect to the firstconductive layer 210, and thus it is preferable to electrically connectthe first conductive layer 210 through the connection pattern 271.

A height of the separation groove 280 may be the same as that of theinterconnection groove 290. That is, a depth of the separation groove280 may be the same as that of the interconnection groove 290. Since theseparation groove 280 and the interconnection groove 290 are formed tohave the same height, the separation groove 280 and the interconnectiongroove 290 may be formed as device having the same property, and thusthere is an effect of reducing a manufacturing cost.

An upper surface of the connection pattern 271 is connected to a firstinterconnect A, and an upper surface of the second conductive layer 270is connected to a second interconnect B, and here, a bonding methodthereof may be any known bonding method such as a welding method.

According to the electrochromic device having the above-describedstructure of the described technology, since the electrochromic deviceis formed to cover a conventional electrochromic layer, does not need tohave a transparent metal grid in an infrared range, and accordingly, thestructure may be formed through only a simple stacking and etchingprocess, so that the process thereof is simple.

In addition, in the related art in which opposing upper and lowersubstrates are used, an additional via structure or guide structure isneeded to connect an upper surface of a second conductive layer 270 anda first interconnect A, whereas in the case of the embodiment, sinceonly one substrate in contact with the first conductive layer 210 isneeded, an additional via structure may be omitted, and thus there is aneffect of easy connection with the interconnect.

In addition, since the first conductive layer 210 and the secondconductive layer 270 which are oxide conductive layers configured toinduce electrochromism are vertically disposed, electrochromism may moreeasily induced.

Next, a manufacturing method of the electrochromic device according tothe second embodiment of the described technology will be described.FIGS. 13 to 17 are a manufacturing process diagram of FIG. 12. First,referring to FIG. 13, the first conductive layer 210 is deposited on alower substrate (not shown) having a transparent material using asputtering method or the like. The ion storage layer 240, theelectrolyte layer 250, and the electrochromic layer 260 are sequentiallydeposited on the first conductive layer 210 as illustrated in FIG. 14.Here, each of the layers constituting the intermediate layer 230 may beformed using a method such as a sputtering method.

In addition, as illustrated in FIG. 15, the interconnection groove 290is formed to expose the inner surface of the first conductive layer 210using a method such as a scribing, laser etching, etching method or thelike.

Next, as illustrated in FIG. 16, using a sputtering method or the like,a conductive layer 273 is formed to cover an outer surface of theelectrochromic layer 260 while the interconnection groove 290 is filledwith the conductive layer 273.

In addition, as illustrated in FIG. 17, the separation groove 280passing through the electrolyte layer 250 from the outside of the secondconductive layer 270 is formed in the inner region of theinterconnection groove 290. Since the electrolyte layer 250 is dividedinto the inner region and the outer region by the separation groove 280,electricity transmission can be blocked therebetween.

In addition, the second conductive layer 270 is formed at an inner sideof the conductive layer 273 and the connection pattern 271 is formed atan outer side of the conductive layer 273 with respect to the separationgroove 280.

In addition, as illustrated in FIG. 12, the connection pattern 271 isconnected to the first interconnect A, and the second conductive layer270 is connected to the second interconnect B, to which electricity maybe applied, through a welding method or the like.

After the second conductive layer 270 and the connection pattern 271 areformed as described above, a manufacturing is completed by stacking anupper substrate (not shown) thereon through a predetermined method.

The above-described electrochromic device according to the describedtechnology can be formed through a simple stacking and etching process,so that a manufacturing process can be simplified.

In addition, in compression to the related art, since the firstconductive layer 210 and the second conductive layer 270, which areconductive oxide layers, are vertically formed, electrochromism can bemore easily induced.

The scope of the present invention is not limited to the above-describedembodiments, and the present invention may be made through variousembodiments within the appended claims. Various ranges that may bechanged by those skilled in the art without departing from the gist ofthe present invention claimed by the appended claims are within theclaims of the present invention.

Although the present invention has been described and illustrated withthe accompanying drawings, the present invention is not limited to theconfiguration and the operations illustrated and described, and it willbe easily understood by those skilled in the art that the presentinvention may be variously changed and modified without departing fromthe spiritual range of the present invention. Therefore, the variouschanges, modifications, and equivalents will also fall within the scopeof the present invention.

What is claimed is:
 1. An electrochromic device comprising: atransparent conductive layer; an ion storage layer; an electrolytelayer; an electrochromic layer; and a reflective layer or a transparentconductive layer, wherein the ion storage layer includes an iridium atomand a tantalum atom, wherein the electrolyte layer includes a tantalumatom, wherein the electrochromic layer includes a tungsten atom, whereinat least one of the tungsten atom of the electrochromic layer and theiridium atom and the tantalum atom of the ion storage layer ishydrogenated, wherein the reflective layer is non-porous, and whereinthe ion storage layer includes 14.9-73.3 wt % of iridium atoms to thetotal weight of the iridium atoms and the tantalum atoms.
 2. Theelectrochromic device of claim 1, wherein the transparent conductivelayer includes at least one kind of oxide selected from: an indium zincoxide (IZO), an indium tin oxide (ITO), an aluminum doped zinc oxide(AZO), a boron doped zinc oxide (BZO), a tungsten doped zinc oxide (WZO)and a tungsten doped tin oxide (WTO), a fluorine doped tin oxide (FTO),a gallium doped zinc oxide (GZO), an antimony doped tin oxide (ATO), anindium doped zinc oxide (IZO), a niobium doped titanium oxide and a zincoxide(ZnO).
 3. The electrochromic device of claim 1, wherein the ionstorage layer includes 20-38 wt % of iridium atoms to the total weightof the iridium atoms and the tantalum atoms.
 4. The electrochromicdevice of claim 1, wherein the ion storage layer includes a hydrogenatediridium oxide of a formula H_(a)lrO₂(herein, 0<a<2) and a hydrogenatedtantalum oxide of a formula H_(b)Ta₂O₅(herein, 0<b<5).
 5. Theelectrochromic device of claim 1, wherein the electrochromic layerincludes a hydrogenated tungsten oxide of a formula H_(C)WO₃(herein,0<c<3).
 6. The electrochromic device of claim 1, wherein the reflectivelayer comprises at least one kind of material selected from an aluminum,a silver, a rubidium, a molybdenum, a chromium, a ruthenium, a gold, acopper, a nickel, a lead, a tin, an indium and a zinc.
 7. Theelectrochromic device of claim 1, a thickness of the transparentconductive layer is 150-800 nm, a thickness of the ion storage layer is50-500 nm, a thickness of the electrolyte layer is 180-800 nm, athickness of the electrochromic layer is 140-650 nm, and a thickness ofthe reflective layer is 30-280 nm.
 8. The electrochromic device of claim1, wherein the ion storage layer includes 14.9-59.8 wt % of iridiumatoms to the total weight of the iridium atoms and the tantalum atoms.9. The electrochromic device of claim 1, wherein the ion storage layerincludes 14.9-23.2 wt % of iridium atoms to the total weight of theiridium atoms and the tantalum atoms.
 10. The electrochromic device ofclaim 1, wherein the ion storage layer includes 20.2-23.2 wt % ofiridium atoms to the total weight of the iridium atoms and the tantalumatoms.